Forces loyal to Libyan leader Muammar Gaddafi fired on a crowd of unarmed people in the rebel-held city of Misrata on Monday and are using civilians as human shields against air strikes, residents said.

The reports from Misrata, the only big rebel stronghold left in western Libya, could not be independently verified and there was no immediate comment from Libyan officials.

One resident said civilians had come out into the streets in the centre of Misrata to confront pro-Gaddafi forces who had earlier moved tanks and men into the city in an apparent effort to avoid being hit by Western jets and missiles.

"When they gathered in the centre, the Gaddafi forces started shooting at them with artillery and guns. They committed a massacre. The hospital told us at least nine people were killed," the man, called Saadoun, told Reuters by telephone.

"The death toll is higher because it just happened now and more than 50 were wounded. The hospital does not have enough space or capability to deal with wounded who keep coming in."

Earlier, a rebel spokesperson told Reuters that pro-Gaddafi forces were bringing civilians from nearby towns into Misrata to use as human shields.

"The Gaddafi forces are forcing people from Zawiyat al Mahjoub and Al Ghiran out of their houses and giving them Gaddafi's pictures and the (official Libyan) green flag to chant for Gaddafi," said Hassan, the rebel spokesman.

"They are bringing them to Misrata so they can enter the city and control it by using the civilians as human shields because they know we are not going to shoot women and children and old people," he said by telephone from Misrata.

Libyan authorities have prevented journalists from reaching Misrata, which is 200 km (130 miles) east of the capital.

Libyan state television broadcast a statement calling on the people of Misrata to "go out of their homes and resume normal life in the city after clearing it from the criminal armed gangs", a term Libyan officials use to describe the rebels.

The accounts from residents appeared to show that Gaddafi's forces, in a change of tactics forced on them by Western air strikes, were trying to mingle with the civilian population, making it difficult to target them from the air.

ABORTED MISSION

Britain's Ministry of Defence said its warplanes aborted a mission overnight because civilians were close to its target.

"As the RAF GR4 Tornados approached the target, further information came to light that identified a number of civilians within the intended target area. As a result the decision was taken not to launch weapons," said Major General John Lorimer, the Chief of Defence Staff's strategic communications officer.

The rebel spokesperson also said seven people were killed in Misrata in fighting on Sunday. "An old man went to dawn prayers, he was shot and his body is still lying in the street as ambulances could not take it to the hospital," he said.

A Misrata resident called Mohamed told Reuters by phone snipers had been posted on rooftops along Tripoli Street, the main thoroughfare, and that tanks were in the centre of Misrata.

"The town is surrounded (by Gaddafi's forces) ... Some armed men dressed in civilians entered the town yesterday. They're stationed at a vocational training institute in the centre of the town. They are protected by the snipers and tanks."

He said water supplies to Misrata had still not been restored after they were cut off last week.

Another resident who did not want to be identified echoed the accounts of Gaddafi forces using civilians to shield them.

"They are taking people hostage so the resistance cannot engage them," the resident said.

"They are trying to infiltrate inside the city to be protected from international community forces."